Planet of the Spiders - S11-E5
Plot hole: At the climax of episode 2, the Doctor is about to catch Lupton when the latter simply teleports to safety. So why didn't he do that in the first place, before engaging in a 15-minute chase?
Invasion of the Dinosaurs - S11-E2
Other mistake: The Tyrannosaurus rex which appears in this story does not actually roar; instead it says the word 'roar' several times. There may be little scientific evidence as to what sound a T. Rex made, but it is unlikely that any of them spoke fluent English.
Plot hole: How did UNIT soldiers manage to get the TARDIS through an ordinary door into the Doctor's dorm in the research centre? The Doctor's labs in the various UNIT HQs had either double doors or a removable partition wall. The research centre is supposed to be an ordinary country house with single doors and solid walls. The TARDIS is larger than the average wardrobe and, unlike most modern wardrobes, doesn't come apart so it can be got through doorways. The TARDIS is known to be a "Type 40 capsule"...but there's never been any mention of the TARDIS being an IKEA-style "flat pack self-assembly" time machine...
Invasion of the Dinosaurs - S11-E2
Revealing mistake: At the beginning of episode two, the soldiers firing at the dinosaur are aiming up and well to the left of the creature.
Invasion of the Dinosaurs - S11-E2
Continuity mistake: In episode 2, when the Doctor and Brig arrive at the scene to stun the dinosaur, they leave the stun gun in the jeep. Mike Yates glances down at it and we can see that the sabotage disk is already attached - although he doesn't actually put it on until later.
Audio problem: When Irongron fires his first gun, the sound is heard before the gun actually fires.
The Monster of Peladon - S11-E4
Revealing mistake: Eckersley - who supposedly knows the mines better than even the natives of Peladon - drags the queen through the same set twice, once each way.
Revealing mistake: In episode three, when the root attacks The Daleks in the mining area, the string holding the root up can be seen.
Revealing mistake: During episode three, in the mining area, just before the city's root appears, the tracks on which The Daleks move can be seen.
The Monster of Peladon - S11-E4
Revealing mistake: When the Doctor and Sarah arrives in episode one, they leave the doors of the TARDIS open and the empty inside of the TARDIS can be seen.
Other mistake: After Linx plants his flag in the ground claiming Earth, Irongron and Bloodaxe look offscreen for no reason, as though the shot is finished.
Factual error: How did potatoes come to appear in a 12th century kitchen? The potato was unknown in England until Sir Walter Raleigh brought them from back from the Americas on one of his voyages in the late 16th century, at least 400 years after the period in which this story is set.
Invasion of the Dinosaurs - S11-E2
Visible crew/equipment: In episode 4, when the Doctor is in the Whomobile, a dark cylindrical object passes in front of the camera in the foreground. It's not something of the Doctor's, as his hands are inside the vehicle.
Invasion of the Dinosaurs - S11-E2
Continuity mistake: In episode 3, Sarah is hit on the head by debris knocked loose by the escaping dinosaur. It hits her on the back of her head or shoulders - but the later bruises and scratches are on her forehead.
The Monster of Peladon - S11-E4
Continuity mistake: In episode three, Eckersley turns on the security monitor. The very first image is of the entrance to the refinery, but it does not show the Doctor and Gebek trying to break in. Eckersley then flips through the images and finds one of the refinery with the Doctor and Gebek breaking in.
Planet of the Spiders - S11-E5
Revealing mistake: In episode three, when Tommy peers into the room where the Doctor and Sarah are talking to Cho-Je, the camera moves forward - and bumps into a wall with an audible thud and noticeable jerk.
Revealing mistake: The explosion of Irongron's castle is obviously stock footage of a quarry explosion.
The Monster of Peladon - S11-E4
Revealing mistake: At the end of episode 2 / beginning of episode 3, the Doctor and Sarah are thrown into a pit. It is quite obvious that they hit a flexible mat when they land. it is gone when they stand up.
The Monster of Peladon - S11-E4
Plot hole: The temperature of the air being blown into the mines is controlled from the communications room when the Doctor needs to knock out The Ice Warriors. But conveniently, the ventilation system is controlled from the refinery when Eckersley needs to suffocate the miners.
The Monster of Peladon - S11-E4
Continuity mistake: When opening the door to the refinery, the Doctor leaves his sonic screwdriver on top of the panel. However, a few seconds later, when we next see the panel, the sonic screwdriver has disappeared.
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB